/* -*- Mode: C; c-basic-offset:4 ; -*- */
/*
 *
 *  (C) 2003 by Argonne National Laboratory.
 *      See COPYRIGHT in top-level directory.
 */
#include "mpi.h"
#include <stdio.h>
#include <stdlib.h>
#include "mpitest.h"

/*
static char MTEST_Descrip[] = "Create a communicator with a graph that contains null edges and one that contains duplicate edges";
*/

int main( int argc, char *argv[] )
{
    int errs = 0;
    int *index = 0, *edges = 0;
    int rank, size, i, j, crank, csize;
    MPI_Comm comm;

    MTest_Init( &argc, &argv );

    MPI_Comm_size( MPI_COMM_WORLD, &size );
    MPI_Comm_rank( MPI_COMM_WORLD, &rank );

    index = (int *)malloc( size*sizeof(int) );
    edges = (int *)malloc( size*sizeof(int) );
    for (i=0; i<size; i++) {
	index[i] = 1;
	edges[i] = i;
    }
    /* As of MPI 2.1, self edges are permitted */
    MPI_Graph_create( MPI_COMM_WORLD, size, index, edges, 0, &comm );
    MPI_Comm_rank( comm, &crank );
    MPI_Comm_size( comm, &csize );
    if (csize != size) {
	errs ++;
	fprintf( stderr, "Graph create with self links has size %d should be %d", csize, size );
    }
    free( index );
    free( edges );
    MPI_Comm_free( &comm );

    /* Create a graph with duplicate links */
    index = (int *)malloc( size * sizeof(int) );
    edges = (int *)malloc( size * 2 * sizeof(int) );
    j = 0;
    for (i=0; i<size; i++) {
	index[i]   = j + 2;
	edges[j++] = (i + 1) % size;
	edges[j++] = (i + 1) % size; 
    }
    /* As of MPI 2.1, duplicate edges are permitted */
    MPI_Graph_create( MPI_COMM_WORLD, size, index, edges, 0, &comm );
    MPI_Comm_rank( comm, &crank );
    MPI_Comm_size( comm, &csize );
    if (csize != size) {
	errs ++;
	fprintf( stderr, "Graph create with duplicate links has size %d should be %d", csize, size );
    }
    free( index );
    free( edges );
    MPI_Comm_free( &comm );

    MTest_Finalize( errs );
    MPI_Finalize();
    return 0;
}
